Bonded abrasive products containing sintered sol gel alumina abrasive filaments

Abstract

Resinoid and vitrified bonded abrasive products containing filament shaped sintered alumina based abrasive made up predominantly of fine alpha alumina crystals.

What is claimed is: 
     
       1. A bonded abrasive product comprised of a sintered sol gel filament shaped alumina based abrasive and a bond therefor wherein said filament shaped alumina based abrasive has an average aspect ratio of at least 1.5, a hardness of at least 16 GPa, and is comprised predominantly of sintered alpha alumina crystals having a size of less than about 2 microns. 
     
     
       2. The bonded abrasive product of claim 1 wherein said sintered abrasive is a seeded sol gel filament shaped abrasive. 
     
     
       3. The bonded abrasive product of claim 2 wherein said sintered filament shaped alumina based abrasive has a density of at least 95% of theoretical density, and includes from 1% to 50% by weight of a material selected from the group consisting of zirconia, titania, magnesia, ceria, spinel, hafnia, mullite, manganese dioxide, precursors of these oxides, and mixtures thereof. 
     
     
       4. The bonded abrasive product of claim 2 wherein said sintered filament shaped alumina based abrasive has an aspect ratio of from 1.5 to 25, a diameter of from 0.001 mm to 2 mm, and said alpha alumina crystals have a size of less than about 1 micron. 
     
     
       5. The bonded abrasive product of claim 4 wherein said alpha alumina crystals have a size of less than about 0.4 micron. 
     
     
       6. The bonded abrasive product of claim 1 wherein said filament shaped alumina based abrasive is curved in its longer dimension. 
     
     
       7. The bonded abrasive product of claim 1 wherein said filament shaped alumina based abrasive is twisted in its longer dimension. 
     
     
       8. The bonded abrasive product of claim 4 wherein said filament shaped alumina based abrasive is curved in its longer dimension. 
     
     
       9. The bonded abrasive product of claim 4 wherein said filament shaped alumina based abrasive is twisted in its longer dimension. 
     
     
       10. The bonded abrasive product of claim 1, wherein said bonded abrasive product consists of 3% to 39% by volume of bond, 30% to 56% by volume of abrasive, and 5% to 67% by volume of pores, and wherein said bond is a vitrified bond. 
     
     
       11. The bonded abrasive product of claim 1, wherein said bonded abrasive product consists of 5% to 76% by volume of bond, 24% to 62% by volume of abrasive, and 0% to 71% by volume of pores, and wherein said bond is a resinoid bond. 
     
     
       12. The bonded abrasive product of claim 10 wherein said abrasive product includes, in addition to said sintered filament shaped alumina based abrasive, 1% to 90% by volume of a second abrasive selected from the group consisting of fused alumina, cofused alumina-zirconia, non-fiber shaped sintered alumina, non-fiber shaped sintered alumina-zirconia, silicon carbide, cubic boron nitride, diamond, flint, garnet, bubbled alumina, bubbled alumina-zirconia, and mixtures thereof. 
     
     
       13. The bonded abrasive product of claim 11 wherein said abrasive product includes, in addition to said sintered filament shaped alumina based abrasive, 1% to 90% by volume of a second abrasive selected from the group consisting of fused alumina, cofused alumina-zirconia, non-fiber shaped sintered alumina, non-fiber shaped sintered alumina-zirconia, silicon carbide, cubic boron nitride, diamond, flint, garnet, bubbled alumina, bubbled alumina-zirconia, and mixtures thereof. 
     
     
       14. The bonded abrasive product of claim 10 wherein said vitrified bond includes 0% to 30% by volume of a filler. 
     
     
       15. The bonded abrasive product of claim 14 wherein said filler is selected from the group consisting of kyanite, mullite, nepheline syenite, graphite, molybdenum disulfide, and mixtures thereof. 
     
     
       16. The bonded abrasive product of claim 11 wherein said resinoid bond includes 0% to 75% by volume of a filler. 
     
     
       17. The bonded abrasive product of claim 16 wherein said filler is selected from the group consisting of cryolite, iron sulfide, calcium fluoride, zinc fluoride, potassium fluoroborate, potassium sulfate, zinc chloride, ammonium chloride, kyanite, mullite, nepheline syenite, molybdenum disulfide, graphite, sodium chloride, copolymers of vinyl chloride and vinylidene chloride, polytetrafluoroethylene, and mixtures thereof. 
     
     
       18. The bonded abrasive product of claim 11 including from 1% to 35% by volume of a pore inducing medium selected from the group consisting of hollow glass beads, solid glass beads, hollow resin beads, solid resin beads, foamed glass particles, bubbled alumina, porous clay particles, and mixtures thereof. 
     
     
       19. The bonded abrasive product of claim 11 wherein said resinoid bond is one selected from the group consisting of phenol-formaldehyde, epoxy, polyurethane, polyester, shellac, rubber, polyimide, polybenzimidizole, phenoxy, and mixtures thereof. 
     
     
       20. The bonded abrasive product of claim 10 wherein said product is a tool sharpening wheel. 
     
     
       21. The bonded abrasive product of claim 10 wherein said product is a segmental wheel. 
     
     
       22. The bonded abrasive product of claim 10 wherein said product is a precision grinding wheel. 
     
     
       23. The bonded abrasive product of claim 10 wherein said product is a creep feed wheel. 
     
     
       24. The bonded abrasive product of claim 11 wherein said product is a cut-off wheel. 
     
     
       25. The bonded abrasive product of claim 11 wherein said product is a portable wheel.